Mosquitofish in Fairfax County, VA

Hello all.

I am the current student representative on Fairfax County's Environmental Quality Advisory Council (EQAC) and was wondering whether NANFA might be willing to weigh in with the organization's stance, if one exists. EQAC is charged with presenting an Annual Report on the Environment to the County Board of Supervisors containing recommendations on issues ranging from light pollution to water resources.

I was reading through the "Wildlife and the Environment" chapter in the most recent report (see here) when I came across the following statement on page 249:

i. Mosquito Habitat Elimination

An important preventive measure to reduce the chance of infection with West Nile Virus is to eliminate, wherever possible, standing water that provides a breeding habitat for mosquitoes. Any containers such as cans, pails, wheelbarrows, etc., should be emptied and stored in such fashion that water will not collect in them. Bird baths and similar containers should have the water changed every two or three days. Ponds can be stocked with the small fish Gambusia that feed on mosquito larvae. There are two species: Gambusia affinis and G. holbrooki. Both are highly effective in keeping ponds and lakes free of mosquito larvae. Gambusia affinis, the most common species, has become endemic in many areas of Eastern Virginia and can be readily transplanted from one pond to another.

I found this peculiar for two main reasons: (1) "becoming endemic" an odd turn of phrase -- though its meaning in epidemiology is rather fitting -- and (2) the specific mention of G. affinis as suitable for transplantation ... when it, unlike G. holbrooki, is not native to Eastern Virginia, was also rather strange.

I may be able to have some say on wording of this section in future Report editions and on the content of EQAC's upcoming citizen action/stewardship publication.

Your thoughts? I will be bringing up the issue at tonight's meeting.

"has become highly endemic" is definately not the correct choice of words. There is plenty of evidence that mosquitofish contrary to their "highly effective ability" to keep ponds mosquito free. That doesn't even get into the ramifications of moving from one body of water to another and native displacement.

Yes, transplantation of G. holbrooki within Fairfax County is one thing, but evident support for adding G. affinis into the mix is troublesome even from the standpoint of hybridization potential between the two species. What's more, if I'm reading them correctly, VA regs governing introduction for mosquito control purposes seem to be more stringent than the passage implies.

Edited by Ouassous, 11 February 2009 - 04:02 PM.